JPH0219098A - Command transmitter-receiver - Google Patents

Abstract

PURPOSE:To attain a narrow band for a receiver and to prevent deterioration in an S/N by mounting a phase synchronizing circuit to synchronize a frequency of a local oscillator in a transmitter with the frequency of an oscillator in a receiver prior to the launching of a flying object in the transmitter. CONSTITUTION:A local signal 24 from a receiver is inputted is a phase comparator 13 prior to the launching through a connector 18 and the frequency of a phase synchronizing circuit 11 is kept to the same frequency by a phase locked loop. The connector 18 is disconnected after the launching and one input to the phase comparator 13 is interrupted, then the phase locked loop is opened. However, a hold signal 16 is sent to a sample-and-hold circuit 16 at the same time of launching and a control voltage applied to a voltage controlled oscillator 12 just before the launching is held. Thus, the carrier frequency of an intermediate frequency signal 26 being inputted to the demodulator 27 is not deviated from the carrier frequency at the sender side even after the launching. Thus, the band is made narrow without changing the hardware scale and the deterioration in the S/N is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is mounted on an aircraft and sends a command signal to give direction to a flying object launched from the aircraft. The present invention relates to a transmitter/receiver in a transmitter/receiver system.

[Conventional technology]

FIG. 2 is a diagram showing a conventional command transmitter/receiver. In FIG. 1, (1) is a transmitter mounted on an aircraft.

(2) is a receiver mounted on the flying object.

In the transmitter (1), (3) is transmission command data.

(4) is a modulator that modulates the transmission command data (3);
(to) a modulator (4) and an oscillator for supplying the K carrier wave (6).

(7) is a modulated wave output from the modulator (4), (8) is an amplifier that amplifies the modulated wave (7), (9) is a transmitting antenna, and 01 is a carrier wave.

In the receiver (2), a is the receiving antenna, CII is the amplifier, C211 is the received signal amplified by the amplifier (to), 4 is the frequency converter, and (to) is the local signal @ to the frequency converter (2). @ is an amplifier, ce is an amplified intermediate frequency signal, plow is a demodulator that demodulates the intermediate frequency signal (to), and cs is received command data demodulated by the demodulator.

Next, the operation will be explained.

In the transmitter +11 mounted on the aircraft, the transmitted command data (3) is modulated by a modulator (4) to become a modulated wave (7). During modulation, the carrier wave (6) is the oscillator (2)
Supplied from. The modulated wave (7) is amplified by an amplifier (8).

It is transmitted from the transmitting antenna (9) as a carrier wave + IQ.

In the receiver (2) mounted on the flying object, the carrier wave α received by the receiving antenna α is amplified by the amplifier (to) and becomes a received signal e2D. This received signal c2D is frequency-converted by a frequency converter (2) using a local signal supplied from an oscillator (to), and then sent to a demodulator as an intermediate frequency signal (to) via an amplifier (to). is input. The received command data (to) is then extracted by the demodulator (2).

[Problem to be solved by the invention]

As described above, the conventional command transmitter/receiver has separate local oscillators built in on the transmitting side and the receiving side.

In general, frequency deviations occur in oscillators due to environmental conditions, etc., so the oscillation frequencies for transmitting and receiving each deviate from the initial setting values. This deviation becomes a frequency deviation of the intermediate frequency signal (1) input to the demodulator gradient.

In the demodulator gradient, in order to perform demodulation, the demodulating bandwidth must be wide enough to accommodate the deviation. If the bandwidth is much wider than the data rate of command data, the s1m ratio of the demodulated signal deteriorates, resulting in deterioration of reception performance.

As an example, the carrier frequency of the transmitted wave 0 is IQ, 14G
Hz.

Assume that the local signal @ of the receiver is 10 GIlz, and the data rate of command data (3) and (2) is 10 KHz.

Temperature stability of oscillator (to) and (2) to ±50 ppm
shall be. In aircraft, the temperature conditions are -40°C to +8°C.
The temperature is extremely severe at 0℃. First, the oscillator on the transmitting side is ±50pp.
If the carrier wave α [is IQ, 14 GHz x (
±50 ppm) - ±501 KHz.

On the receiving side, in addition to this deviation, the receiving side oscillator deviation is 100
)lzx(±50ppm)-±500 KHz,
Together with the transmitting side, the deviation exceeds ±I MHz. Here, the data rate of the command data on the sending side is 10KH.
If there is no frequency deviation in the oscillator built into the transmitter/receiver, demodulation is possible in a band of 10 KHz, but in reality, a band of ±1007 KHz is required due to the deviation in the oscillator. this is.

The deterioration is approximately 23 dB at an 8/N ratio.

This invention was made to solve these problems, and it is an object of the present invention to obtain a command transmitter/receiver that can narrow the band, prevent S/N deterioration, and improve reception performance without changing the receiver hardware scale. With the goal.

[Means to solve the problem]

The command transceiver according to the present invention synchronizes the phase synchronization circuit in the transmitter with the oscillator in the receiver.

Even after a projectile is launched, it can maintain the same frequency as before the launch.

[Effect]

The command transmitter/receiver according to the present invention incorporates a phase synchronization circuit in the transmitter and an oscillator in the receiver.
It is possible to narrow the band without changing the hardware scale of the receiver and prevent deterioration of the 8/N ratio.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In Figure 1, αυ is a phase-locked circuit, (5) is a multiplier, a is a voltage-controlled oscillator, (11 is a voltage-controlled oscillator (
A phase comparator that receives the output of I2 and the local signal on the receiving side as input, α-hiro is a loop filter, Q9 is a sample-hold circuit that holds the output of loop filter α-hiro using a hold signal αe, and aS should be skipped. A connector that connects the transmitter and receiver before launch.

The main part is a hold signal generator that outputs a hold signal when launching a flying object.

Next, the operation will be explained.

0 phase comparator (13) before launching the projectile.

A local signal @ is input from the receiving side via the connector, and the first phase locked circuit αυ is already kept at the same frequency in the phase locked loop. At this time, the sample hold circuit clcJ transmits the output of the loop filter α as it is to the tortoise pressure control generator a'a.

After launching the flying object, the connector AS becomes disconnected.

Since one input to the phase comparator α3 is disconnected, the phase locked loop becomes open. However, at the same time as the 9th firing, a hold signal aQ is sent to the sample and hold circuit α9, and the control voltage that was applied to the voltage controlled oscillator a immediately before the 9th firing is held. Therefore, the output of the voltage controlled oscillator α remains at the same frequency as before one firing. Therefore, the multiplier (
The output of 5), that is, the local signal for reception (6), is maintained at the same frequency as the local signal on the transmitting side even after being emitted.

In the demodulator (5), since the input intermediate frequency signal (to) does not deviate from the carrier frequency on the transmitting side even after being emitted, it is possible to narrow the band.

Deterioration of the 8A ratio of the demodulated signal can be prevented.

In the above embodiment, the hold signal generator ση is used to give the hold signal ae to the sample-and-hold circuit aS on the transmitter side. It may also be configured to maintain the frequency before the launch while the body is about to fly.

〔Effect of the invention〕

As described above, according to the present invention, the transmitter is equipped with a phase synchronization circuit that matches the frequency of the local oscillator in the transmitter with the oscillator in the receiver before launching the flying object. The receiver installed in the B7'H has the conventional configuration L: The receiver has a narrower band and is effective in preventing deterioration of the B7'H ratio.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a command transmitter/receiver according to an embodiment of the present invention, and FIG. 2 is a diagram showing a conventional command transmitter/receiver. (1) is a transmitter, (2) is a receiver, and Qυ is a phase locked circuit. α1 is the sample hold circuit or connector. In addition, in FIG. 1, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In a transmission/reception system that transmits command signals from an aircraft to a flying object, a transmitter is mounted on the aircraft and a receiver is mounted on the flying object launched from the aircraft. A connector that supplies a carrier wave to the transmitting side, a phase synchronization circuit that obtains a transmitting local oscillation frequency of the same frequency as the carrier frequency from the receiving side on the transmitting side, and a phase synchronization circuit that provides a transmitting local oscillation frequency that is the same as the carrier frequency from the receiving side. Command transceiver with sample and hold circuit to keep the same frequency.